Skip to content

Cold, Flu, & Cough Health Center

Select An Article

Flu Complications

Font Size

Worried about flu complications? Even for a healthy person, the flu can put you out of commission for days -- even weeks. And there's always the chance that the flu can cause more serious health problems or flu complications such as sinusitis (sinus infections), bronchitis, or even pneumonia.

According to the CDC, 5% to 20% of the U.S. population contracts the flu annually. More than 200,000 of those individuals are hospitalized for flu complications.

Recommended Related to Cold & Flu

How Flu Spreads

Person to Person The main way that influenza viruses are thought to spread is from person to person in respiratory droplets of coughs and sneezes. (This is called "droplet spread.") This can happen when droplets from a cough or sneeze of an infected person are propelled through the air and deposited on the mouth or nose of people nearby. Influenza viruses may also be spread when a person touches respiratory droplets on another person or an object and then touches their own mouth or nose (or someone...

Read the How Flu Spreads article > >

Over a period of 30 years, between 1976 and 2006, estimates of flu-associated deaths in the United States range from a low of about 3,000 to a high of about 49,000 people.

What Is the Flu?

Influenza -- commonly shortened to "flu" -- is an extremely contagious viral disease that appears most frequently in the fall and winter. The flu comes on fast and strong, spreading through your upper respiratory tract and sometimes invading your lungs.

What Are the Symptoms of the Flu?

With the flu, you may have the following symptoms:

(For more information about flu symptoms, see WebMD's Flu Symptoms: What You Might Feel.)

What Are Common Flu Complications?

The most common flu complications include viral or bacterial pneumonia, ear infections and sinus infections, especially in children, dehydration, and worsening of chronic medical conditions, such as congestive heart failure, asthma, or diabetes.

Other complications include muscle inflammation (myositis), central nervous system disease, and heart problems including heart attacks, inflammation of the heart muscle (myocarditis), and inflammation of the sac around the heart (pericarditis).

Those at highest risk for flu complications include adults over 65, children ages 6 months to 4 years, nursing home residents, adults and children with heart or lung disease, people with compromised immune systems (including people with HIV/AIDS), and pregnant women.

(For in-depth information, see WebMD's Flu and Chronic Medical Conditions.)

Is Pneumonia a Serious Flu Complication?

Yes, pneumonia is a common and very serious flu complication. Pneumonia can occur from direct involvement of the flu virus in the lung or when a bacterial infection develops during the course of the flu. Whether viral or bacterial, pneumonia can make you quite ill and may require hospitalization.

Next Article:

Today on WebMD

hot toddy
15 tips to help you feel better.
man sneezing into elbow
Do echinacea and vitamin C really help a cold?
teen girl coughing
Get a good night’s rest with these remedies.
elder berry
Eat these to fight colds, flu, and more.
Natural Cold Flu Remedies Slideshow
cold weather
Allergy And Sinus Symptom Evaluator
Boy holding ear

Loaded with tips to help you avoid food allergy triggers.

Loading ...

Sending your email...

This feature is temporarily unavailable. Please try again later.


Now check your email account on your mobile phone to download your new app.

woman receiving vaccine shot
woman with fever
Waking up from sleep
woman with sore throat